After Theorem 2.1 on page 36 (second edition) he states
Note that the argument above shows that if $Q$ is a nontrivial monotone increasing property then
$$P_{p_2}(Q) \ge P_{p_1}(Q) + \{1 - P_{p_1}(Q)\}P_p(Q) \ge P_{p_1}(Q) + P_{p_1}(E^n)P_p(K^n) > P_{p_1}(Q).$$
What are $E^n$ and $K^n$? In the section on notation $E$ is usually some sort of expectation, and the complete graph on $n$ vertices is $K_n$, not $K^n$. Can someone shed some light on this?